Changes to the BPOG protocol have recently happened (April 2020). What does it mean for the end user?
In terms of overall scale the study is a lot smaller in size and also simpler than before. The overall level of testing has more than halved. It has changed from at extreme 6 solvents and 4 timepoints (24 solutions to analyse) to 4 solvents and 3 timepoints (12 solutions to analyse).
The more contentious solvents polysorbate 80 and 5M NaCl have been removed. Testing is no longer required at the initial timepoint as extractable levels are found at higher levels at subsequent timepoints. Also removed is the need to analyse the 50% ethanol solution for metals. Adding in the reduced number of control samples this is a significant reduction in study size.
Other areas of change include widening the testing window for irradiated samples from 5 to 8 weeks. A more detailed explanation around variability of the data, which could be due to a number of factors including: raw materials, manufacturing process, the extraction process and analysis.
Ideally, two components from two different raw material batches should be tested but if this is not possible then two extraction could be from the same batch of material. Further clarification on the actions required depending on the level of solvent loss has been given with the required justification of actions if more than 50% of the solvent is lost during the extraction process.
The revised BPOG protocol can be found at https://www.biophorum.com/wp-content/uploads/Best-practices-guide-for-extractables-testing-April-2020.pdf